Induction of P-450 in Workers Exposed to Dioxin

Overview

Journal Occup Environ Med

Specialties Environmental Health
Occupational Medicine

Date 1995 Feb 1

PMID 7757172

Citations 6

Authors

W Halperin

W KALOW

M H Sweeney

B K Tang

M Fingerhut

B Timpkins

K Wille

Affiliations

Soon will be listed here.

Abstract

Objectives: To examine the effects of occupational exposure to substances contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on cytochrome P-4501A2 activity in a cross sectional medical survey.

Methods: The exposed workers had been employed at two chemical plants > 15 years earlier in the manufacture of 2,4, 5-trichlorophenol and its derivatives. The control group consisted of people with no occupational exposure to phenoxy herbicides and who lived within the communities of the exposed workers. A total of 58 workers and 125 unexposed controls participated in the analysis. Cytochrome P-450 activity was assessed with test that measures caffeine metabolites in the urine. A ratio of metabolites of caffeine (CMR) constituted a measure of P-4501A2 activity.

Results: Compared with the control group in multivariate logistic regression, raised non-significant associations were found for three of four categories of TCDD in exposed workers (TCDD < 20 pg/g, odds ratio (OR) 1.7, 95% confidence interval (95% CI) 0.6 to 5.0, TCDD 20-66, OR 0.3, 95% CI 0.0 to 1.7; TCDD 67-147, OR 2.3, 95% CI 0.6 to 8.8; TCDD > or = 148, OR 3.1, 95% CI 0.8 to 12.5). We found a strongly significant association of CMR and urinary cotinine, a measure of smoking, and urinary free ethanol. We found weak non-significant associations between P-4501A2 activity and increased serum TCDD among workers.

Conclusions: The absence of an association between serum TCDD and cytochrome P-4501A2 may be due to the size of the study, insensitivity of the CMR to assess cytochrome P-4501A2 activity, or inadequate levels of exposure, although these were among the highest in human groups tested.

Citing Articles

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Induction of cytochrome P450 1A by cow milk-based formula: a comparative study between human milk and formula.

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PCB exposure and in vivo CYP1A2 activity among Native Americans.

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Immunological markers among workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

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